RRB Exam Preparation Day 1: 50 Important Pharmacology MCQs with Answers and Explanations

Preparing for the RRB Pharmacist examination requires a strong understanding of Pharmacology, Pharmaceutics, Pharmaceutical Chemistry, and other important pharmacy subjects.

In this 30-Day RRB Pharmacist Preparation Series, we will cover important topics through daily MCQs, correct answers, and explanations to help you revise effectively and prepare for the examination.

For Day 1, we are starting with Pharmacology, one of the essential subjects for pharmacy competitive examinations. These 50 MCQs cover important drug classifications, mechanisms of action, therapeutic uses, adverse drug reactions, antidotes, and commonly tested pharmacological facts.

Attempt all the questions before checking the answers to assess your preparation.

Day 1: Pharmacology MCQs for RRB Pharmacist Exam

Subject: Pharmacology
Total Questions: 50
Difficulty Level: Basic to Moderate
Preparation Goal: Revise high-yield Pharmacology concepts
Recommended Time: 40–45 minutes

Section 1: General Pharmacology

Q1. Which route of drug administration completely avoids first-pass metabolism?

A. Oral
B. Sublingual
C. Rectal
D. Intraduodenal

Correct Answer: B. Sublingual

Explanation: Sublingually administered drugs are absorbed through the oral mucosa and enter systemic circulation without initially passing through the liver. This avoids hepatic first-pass metabolism.

Q2. Which of the following is a competitive antagonist?

A. Phenoxybenzamine at alpha receptors
B. Naloxone at opioid receptors
C. Aspirin at cyclooxygenase
D. Omeprazole at the proton pump

Correct Answer: B. Naloxone at opioid receptors

Explanation: Naloxone competitively blocks opioid receptors and reverses opioid-induced respiratory depression. Phenoxybenzamine is an irreversible, noncompetitive alpha-adrenergic antagonist.

Q3. The term “half-life” of a drug refers to the time required for:

A. Complete elimination of the drug
B. Absorption of half the administered dose
C. Plasma drug concentration to decrease by 50%
D. The drug to reach its maximum concentration

Correct Answer: C. Plasma drug concentration to decrease by 50%

Explanation: The elimination half-life is the time required for the plasma concentration or amount of a drug in the body to decrease by 50% during the elimination phase.

Q4. Which of the following drugs is a potent enzyme inducer?

A. Rifampicin
B. Cimetidine
C. Erythromycin
D. Chloramphenicol

Correct Answer: A. Rifampicin

Explanation: Rifampicin induces several drug-metabolizing enzymes and transporters. It can decrease the effectiveness of medicines such as oral contraceptives and certain anticoagulants.

Q5. Which type of drug interaction occurs when one drug reduces the effect of another?

A. Synergism
B. Potentiation
C. Antagonism
D. Additive effect

Correct Answer: C. Antagonism

Explanation: Antagonism occurs when one drug reduces or opposes the pharmacological effect of another drug. For example, naloxone antagonizes the effects of opioid drugs.

Section 2: Autonomic Nervous System

Q6. Which drug is a selective beta-1 adrenergic blocker?

A. Propranolol
B. Metoprolol
C. Timolol
D. Carvedilol

Correct Answer: B. Metoprolol

Explanation: Metoprolol is relatively selective for beta-1 adrenergic receptors at usual therapeutic doses. It reduces heart rate and myocardial contractility. Its selectivity decreases at higher doses.

Q7. Which drug is commonly used to treat organophosphate poisoning along with atropine?

A. Neostigmine
B. Pralidoxime
C. Pilocarpine
D. Bethanechol

Correct Answer: B. Pralidoxime

Explanation: Pralidoxime can reactivate acetylcholinesterase inhibited by organophosphates if administered before the enzyme undergoes aging. Atropine controls muscarinic effects, while pralidoxime can help reverse certain neuromuscular effects.

Q8. Which of the following is a muscarinic receptor antagonist?

A. Pilocarpine
B. Bethanechol
C. Atropine
D. Neostigmine

Correct Answer: C. Atropine

Explanation: Atropine competitively blocks muscarinic acetylcholine receptors. It is used in conditions such as symptomatic bradycardia and organophosphate poisoning.

Q9. Which drug is primarily used to treat myasthenia gravis?

A. Neostigmine
B. Atropine
C. Adrenaline
D. Propranolol

Correct Answer: A. Neostigmine

Explanation: Neostigmine inhibits acetylcholinesterase, increasing acetylcholine concentration at the neuromuscular junction. It can improve muscle strength in myasthenia gravis.

Q10. Which drug is used in the treatment of anaphylaxis?

A. Adrenaline
B. Atropine
C. Diazepam
D. Digoxin

Correct Answer: A. Adrenaline

Explanation: Adrenaline, also known as epinephrine, is the first-line medicine for anaphylaxis. It produces alpha-1-mediated vasoconstriction and beta-2-mediated bronchodilation, while supporting cardiac function.

Section 3: Cardiovascular Pharmacology

Q11. Which drug is a loop diuretic?

A. Spironolactone
B. Hydrochlorothiazide
C. Furosemide
D. Amiloride

Correct Answer: C. Furosemide

Explanation: Furosemide inhibits the sodium-potassium-2 chloride cotransporter in the thick ascending limb of the loop of Henle. It is used to treat edema and certain cases of hypertension.

Q12. Which of the following is an angiotensin-converting enzyme inhibitor?

A. Losartan
B. Enalapril
C. Amlodipine
D. Atenolol

Correct Answer: B. Enalapril

Explanation: Enalapril inhibits ACE, reducing the formation of angiotensin II and decreasing aldosterone secretion. ACE inhibitors can cause cough, hyperkalemia, and angioedema and are contraindicated during pregnancy.

Q13. Which drug is a potassium-sparing diuretic that blocks aldosterone receptors?

A. Furosemide
B. Mannitol
C. Spironolactone
D. Acetazolamide

Correct Answer: C. Spironolactone

Explanation: Spironolactone blocks mineralocorticoid receptors in the distal nephron, reducing sodium retention and potassium excretion. Hyperkalemia is an important adverse effect.

Q14. Which drug is commonly used for rapid relief of an acute attack of angina pectoris?

A. Sublingual nitroglycerin
B. Oral digoxin
C. Oral simvastatin
D. Oral spironolactone

Correct Answer: A. Sublingual nitroglycerin

Explanation: Nitroglycerin releases nitric oxide, increasing cyclic GMP and relaxing vascular smooth muscle. Venodilation reduces cardiac preload and myocardial oxygen demand.

Q15. Which drug inhibits platelet aggregation by irreversibly inhibiting cyclooxygenase-1?

A. Aspirin
B. Heparin
C. Warfarin
D. Alteplase

Correct Answer: A. Aspirin

Explanation: Aspirin irreversibly inhibits platelet COX-1, reducing thromboxane A2 synthesis and platelet aggregation. Its antiplatelet effect lasts for the lifespan of affected platelets.

Q16. Which anticoagulant is commonly monitored using the international normalized ratio (INR)?

A. Unfractionated heparin
B. Warfarin
C. Aspirin
D. Clopidogrel

Correct Answer: B. Warfarin

Explanation: INR is used to monitor warfarin therapy. Unfractionated heparin is commonly monitored using the activated partial thromboplastin time (aPTT), although other monitoring methods may be used in specific settings.

Q17. Which drug is a cardiac glycoside?

A. Digoxin
B. Amlodipine
C. Losartan
D. Nitroglycerin

Correct Answer: A. Digoxin

Explanation: Digoxin inhibits the sodium-potassium ATPase pump, indirectly increasing intracellular calcium and myocardial contractility. It is used in selected patients with heart failure and for ventricular rate control in atrial fibrillation.

Q18. Which drug is a dihydropyridine calcium channel blocker?

A. Verapamil
B. Diltiazem
C. Amlodipine
D. Digoxin

Correct Answer: C. Amlodipine

Explanation: Amlodipine blocks L-type calcium channels, predominantly producing vascular smooth muscle relaxation. It is commonly used to treat hypertension and angina.

Section 4: Central Nervous System Pharmacology

Q19. Which drug is a benzodiazepine?

A. Phenytoin
B. Diazepam
C. Levodopa
D. Fluoxetine

Correct Answer: B. Diazepam

Explanation: Diazepam enhances GABA-A receptor-mediated inhibition by increasing the frequency of chloride channel opening in the presence of GABA. It is used for anxiety, seizures, muscle spasms, and alcohol withdrawal.

Q20. Which drug is commonly used to treat Parkinson’s disease?

A. Levodopa
B. Haloperidol
C. Fluoxetine
D. Phenytoin

Correct Answer: A. Levodopa

Explanation: Levodopa crosses the blood-brain barrier and is converted into dopamine in the brain. It is usually administered with carbidopa to reduce peripheral conversion and associated adverse effects.

Q21. Which antiepileptic drug is associated with gingival hyperplasia?

A. Phenytoin
B. Ethosuximide
C. Gabapentin
D. Levetiracetam

Correct Answer: A. Phenytoin

Explanation: Phenytoin can cause gingival hyperplasia, hirsutism, nystagmus, and ataxia. Good oral hygiene and regular dental care are important during treatment.

Q22. Which drug is a selective serotonin reuptake inhibitor (SSRI)?

A. Amitriptyline
B. Fluoxetine
C. Phenelzine
D. Lithium

Correct Answer: B. Fluoxetine

Explanation: Fluoxetine inhibits serotonin reuptake by blocking the serotonin transporter. It is used to treat depression and several anxiety-related and obsessive-compulsive disorders.

Q23. Which drug is used to treat opioid overdose?

A. Flumazenil
B. Naloxone
C. Atropine
D. Protamine sulfate

Correct Answer: B. Naloxone

Explanation: Naloxone is an opioid receptor antagonist that can rapidly reverse opioid-induced respiratory depression. Repeat doses and medical observation may be required because its duration of action can be shorter than that of the opioid involved.

Q24. Which drug is a typical antipsychotic?

A. Haloperidol
B. Fluoxetine
C. Diazepam
D. Carbamazepine

Correct Answer: A. Haloperidol

Explanation: Haloperidol is a first-generation antipsychotic that primarily blocks dopamine D2 receptors. Important adverse effects include extrapyramidal symptoms and hyperprolactinemia.

Q25. Which drug is commonly used as an antidote for benzodiazepine overdose in selected cases?

A. Naloxone
B. Flumazenil
C. Vitamin K
D. Deferoxamine

Correct Answer: B. Flumazenil

Explanation: Flumazenil antagonizes the benzodiazepine binding site on GABA-A receptors. Its use is restricted in certain situations because it may precipitate seizures, particularly in patients with benzodiazepine dependence or mixed overdoses involving proconvulsant drugs.

Section 5: Antibiotics and Antimicrobial Agents

Q26. Which antibiotic inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins?

A. Amoxicillin
B. Azithromycin
C. Doxycycline
D. Ciprofloxacin

Correct Answer: A. Amoxicillin

Explanation: Amoxicillin is a beta-lactam antibiotic that binds to penicillin-binding proteins and inhibits bacterial cell wall synthesis. It is active against susceptible bacteria.

Q27. Which antibiotic inhibits bacterial protein synthesis by binding to the 30S ribosomal subunit?

A. Tetracycline
B. Erythromycin
C. Chloramphenicol
D. Clindamycin

Correct Answer: A. Tetracycline

Explanation: Tetracyclines bind reversibly to the 30S ribosomal subunit and inhibit the attachment of aminoacyl-tRNA. They are generally bacteriostatic.

Q28. Which antibiotic inhibits bacterial DNA gyrase and topoisomerase IV?

A. Ciprofloxacin
B. Amoxicillin
C. Erythromycin
D. Vancomycin

Correct Answer: A. Ciprofloxacin

Explanation: Ciprofloxacin is a fluoroquinolone that inhibits bacterial DNA gyrase and topoisomerase IV, interfering with DNA replication. Important adverse effects include tendinitis, tendon rupture, and central nervous system effects.

Q29. Which antibiotic is associated with the risk of red man syndrome, now commonly termed vancomycin infusion reaction?

A. Vancomycin
B. Amoxicillin
C. Doxycycline
D. Azithromycin

Correct Answer: A. Vancomycin

Explanation: Rapid intravenous infusion of vancomycin can cause flushing, itching, and sometimes hypotension. Slowing the infusion and appropriate clinical management can reduce the risk.

Q30. Which drug is commonly used to treat tuberculosis as part of a multidrug regimen?

A. Isoniazid
B. Acyclovir
C. Fluconazole
D. Metronidazole

Correct Answer: A. Isoniazid

Explanation: Isoniazid inhibits the synthesis of mycolic acids, important components of the mycobacterial cell wall. It can cause peripheral neuropathy, which can be reduced by pyridoxine supplementation in appropriate patients.

Q31. Which antibiotic can cause gray baby syndrome?

A. Chloramphenicol
B. Penicillin V
C. Cefalexin
D. Azithromycin

Correct Answer: A. Chloramphenicol

Explanation: Neonates have limited capacity to metabolize chloramphenicol, which can lead to drug accumulation and gray baby syndrome. Chloramphenicol can also cause serious bone marrow toxicity.

Q32. Which antifungal drug inhibits ergosterol synthesis by inhibiting fungal 14-alpha-demethylase?

A. Fluconazole
B. Amphotericin B
C. Nystatin
D. Griseofulvin

Correct Answer: A. Fluconazole

Explanation: Fluconazole is an azole antifungal that inhibits a fungal cytochrome P450 enzyme involved in ergosterol synthesis. Amphotericin B, in contrast, binds to ergosterol and disrupts fungal cell membranes.

Q33. Which antiviral drug is commonly used to treat herpes simplex virus infections?

A. Acyclovir
B. Zidovudine
C. Oseltamivir
D. Sofosbuvir

Correct Answer: A. Acyclovir

Explanation: Acyclovir is activated preferentially in virus-infected cells and inhibits viral DNA polymerase. It is used for infections caused by herpes simplex viruses and varicella-zoster virus.

Section 6: Endocrine Pharmacology

Q34. Which insulin preparation has a rapid onset of action?

A. Insulin lispro
B. Insulin glargine
C. NPH insulin
D. Insulin degludec

Correct Answer: A. Insulin lispro

Explanation: Insulin lispro is a rapid-acting insulin analogue used around mealtimes to control postprandial blood glucose. Insulin glargine and degludec are long-acting preparations.

Q35. Which drug is commonly used as first-line pharmacological treatment for type 2 diabetes in many patients?

A. Metformin
B. Glucagon
C. Adrenaline
D. Hydrocortisone

Correct Answer: A. Metformin

Explanation: Metformin primarily reduces hepatic glucose production and improves insulin sensitivity. Treatment selection depends on the patient’s clinical condition, kidney function, cardiovascular status, and other factors.

Q36. Which drug is used to treat hypothyroidism?

A. Levothyroxine
B. Propylthiouracil
C. Carbimazole
D. Methimazole

Correct Answer: A. Levothyroxine

Explanation: Levothyroxine is synthetic thyroxine (T4). It replaces deficient thyroid hormone and is commonly used for the treatment of hypothyroidism.

Q37. Which drug inhibits thyroid hormone synthesis and is used to treat hyperthyroidism?

A. Levothyroxine
B. Carbimazole
C. Insulin
D. Metformin

Correct Answer: B. Carbimazole

Explanation: Carbimazole is converted to methimazole and inhibits thyroid peroxidase-mediated thyroid hormone synthesis. A serious adverse effect is agranulocytosis; fever or sore throat during treatment requires urgent medical assessment.

Q38. Which hormone is secreted by the beta cells of the pancreatic islets?

A. Glucagon
B. Insulin
C. Somatostatin only
D. Cortisol

Correct Answer: B. Insulin

Explanation: Pancreatic beta cells secrete insulin, which promotes glucose uptake in insulin-sensitive tissues and reduces hepatic glucose production. Glucagon is secreted by pancreatic alpha cells.

Section 7: Gastrointestinal Pharmacology

Q39. Which drug is a proton pump inhibitor?

A. Omeprazole
B. Famotidine
C. Aluminium hydroxide
D. Ondansetron

Correct Answer: A. Omeprazole

Explanation: Omeprazole inhibits the gastric H+/K+-ATPase proton pump in parietal cells, reducing gastric acid secretion. It is used in conditions such as gastroesophageal reflux disease and peptic ulcer disease.

Q40. Which drug is a selective 5-HT3 receptor antagonist used to prevent nausea and vomiting?

A. Ondansetron
B. Metoclopramide
C. Omeprazole
D. Lactulose

Correct Answer: A. Ondansetron

Explanation: Ondansetron blocks serotonin 5-HT3 receptors in the gastrointestinal tract and central vomiting pathways. It is used to prevent or treat nausea and vomiting associated with several conditions.

Q41. Which drug is commonly used as an osmotic laxative?

A. Lactulose
B. Loperamide
C. Ondansetron
D. Loperamide and atropine

Correct Answer: A. Lactulose

Explanation: Lactulose is an osmotic laxative that draws water into the colon and helps soften stools. It is also used to reduce blood ammonia levels in hepatic encephalopathy.

Q42. Which drug is used to reduce intestinal motility in uncomplicated acute diarrhea when appropriate?

A. Loperamide
B. Lactulose
C. Bisacodyl
D. Metoclopramide

Correct Answer: A. Loperamide

Explanation: Loperamide acts on peripheral opioid receptors in the gut to reduce intestinal motility. It should not be used in certain cases, including bloody diarrhea or diarrhea accompanied by high fever, without appropriate medical evaluation.

Section 8: Analgesics and Anti-inflammatory Drugs

Q43. Which drug is a nonselective cyclooxygenase inhibitor commonly used for pain and inflammation?

A. Ibuprofen
B. Paracetamol
C. Morphine
D. Tramadol

Correct Answer: A. Ibuprofen

Explanation: Ibuprofen is a nonsteroidal anti-inflammatory drug (NSAID) that inhibits COX enzymes, reducing prostaglandin synthesis. Adverse effects include gastrointestinal irritation, ulceration, kidney injury, and increased cardiovascular risk in some patients.

Q44. Which drug is an opioid analgesic?

A. Morphine
B. Ibuprofen
C. Aspirin
D. Diclofenac

Correct Answer: A. Morphine

Explanation: Morphine primarily activates mu-opioid receptors and is used for moderate to severe pain. Important adverse effects include respiratory depression, constipation, nausea, and sedation.

Q45. Which drug is associated with hepatotoxicity in overdose?

A. Paracetamol
B. Cetirizine
C. Amoxicillin
D. Famotidine

Correct Answer: A. Paracetamol

Explanation: Excessive paracetamol can produce the toxic metabolite NAPQI, causing severe liver injury when normal detoxification mechanisms are overwhelmed. N-acetylcysteine is the antidote and should be administered promptly when indicated.

Section 9: Antidotes and Toxicology

Q46. Which drug is used as an antidote for heparin overdose?

A. Vitamin K
B. Protamine sulfate
C. Naloxone
D. Atropine

Correct Answer: B. Protamine sulfate

Explanation: Protamine sulfate binds to and neutralizes unfractionated heparin. Its reversal of low-molecular-weight heparins is incomplete.

Q47. Which vitamin is used to reverse the anticoagulant effect of warfarin?

A. Vitamin A
B. Vitamin B12
C. Vitamin K
D. Vitamin D

Correct Answer: C. Vitamin K

Explanation: Vitamin K supports the synthesis of functional clotting factors II, VII, IX, and X. In serious or life-threatening warfarin-associated bleeding, additional treatments such as four-factor prothrombin complex concentrate may be required.

Q48. Which chelating agent is used in the treatment of iron poisoning?

A. Deferoxamine
B. Atropine
C. Flumazenil
D. Naloxone

Correct Answer: A. Deferoxamine

Explanation: Deferoxamine binds iron and forms a complex that can be eliminated from the body. It is used in selected cases of acute iron poisoning and other forms of iron overload.

Q49. Which antidote is used in methanol poisoning to block alcohol dehydrogenase?

A. Fomepizole
B. Vitamin K
C. Protamine sulfate
D. Pralidoxime

Correct Answer: A. Fomepizole

Explanation: Fomepizole inhibits alcohol dehydrogenase, reducing the conversion of methanol into toxic metabolites. Methanol poisoning is a medical emergency that may also require hemodialysis and supportive treatment.

Q50. Which drug is used as an antidote for cyanide poisoning?

A. Hydroxocobalamin
B. Naloxone
C. Flumazenil
D. Deferoxamine

Correct Answer: A. Hydroxocobalamin

Explanation: Hydroxocobalamin binds cyanide to form cyanocobalamin, which can be eliminated in urine. It is an established antidote for serious cyanide poisoning.

Day 1 Quick Revision: Important Pharmacology Facts

Revise these high-yield facts after attempting all 50 questions.

Tips to Improve Your RRB Pharmacist Preparation

1. Attempt each question before checking its answer.
2. Maintain a notebook of incorrect answers and important drug facts.
3. Revise drug classifications, mechanisms of action, adverse effects, and antidotes regularly.
4. Practise questions from previous-year papers when authentic papers are available.
5. Take timed mock tests to improve speed and accuracy.
6. Revise the questions you answered incorrectly before starting the next day’s practice.

Conclusion

Pharmacology is an important subject for pharmacist competitive examinations. Understanding drug mechanisms, therapeutic uses, adverse effects, contraindications, and antidotes can strengthen your preparation.

Complete these 50 MCQs, review your mistakes, and revise the quick-reference table before moving to Day 2.

Continue your preparation with our 30-Day RRB Pharmacist Preparation Series on PharmacyMCQ.in. Practise every day, revise regularly, and build your confidence one subject at a time.

Disclaimer: This article is intended for educational and examination-preparation purposes. The MCQs are practice questions based on established Pharmacology concepts and are not represented as verbatim questions from verified RRB previous-year papers. Always consult the official recruitment notification for the applicable examination syllabus and pattern.